In that post, I briefly touched upon two LBC sub-certification programs that, while not as crazy-rigorous as full Living Building Challenge-dom, aren’t exactly easy to obtain. The first is Petal Recognition, an honor bestowed on projects that don’t meet eligibility of all seven performance areas, or “petals,” required for full certification: Site, Water, Energy, Health, Materials, Equity and Beauty.

The second is Net Zero Energy Building Certification, a program that follows a slightly different set of standards than Living Building and Petal certifications and, of course, focuses heavily on a building's energy usage and production. A couple of projects, such as the remarkably resilient zHome multifamily townhouse development in Issaquash, Wash., have managed to achieve both Petal Recognition and Net Zero Energy Building Certification.

A recent addition to the extremely abbreviated list — currently four total — of Net Zero Energy Building Certified buildings is the regional headquarters of sustainable building firm DPR Construction in Phoenix, Ariz.

Boasting a 79 kilowatt rooftop solar array located over the structure’s parking canopies, a rooftop solar thermal system, and a total of 87 climate-controlled operable windows, the 16,533-square-foot open-office complex — conceptualized as a “net-zero energy workplace of the future” — is a remarkable feat of sustainable building with a whole lot of attention being placed on what the structure used to be: a big ol’ adult bookstore.

Built in the 1970s as a paint store and later converted to house the Castle Megastore, a West Coast/Southwest chain store specializing in “essentials for lovers,” the building sat vacant for three years near the Phoenix Sky Harbor Airport before DPR bought the property in 2010. Upon purchasing the one-time Phoenix outpost of the porn 'n' plaything peddler (those who have visited Castle Megastores are probably well aware that they're much more sanitized than seedy in nature), the company noted that the structure boasted excellent insulation and overall "great bones."

And with that began an eco-minded facelift that transformed the building, described by DPR as “in and of itself a phoenix of sorts,” to the deep-green showpiece that it is today:

Within the built environment of the cities that thrive in our beautiful yet harsh desert climate; architects, planners, engineers and contractors have increasingly moved towards the ideal that it is better to work with Mother Nature than against her. There is a growing desire to better understand the fragile but perfect balance that has existed in the Sonoran Desert for eons and apply its idiosyncrasies to the houses, offices, churches and towers in which we spend most of our lives.

It was in this spirit that we at DPR Construction embarked on our journey to design and construct an edifice that would not only enhance our company’s pride of the office in which they perform their daily tasks but that would complement the existing neighborhood and adjacencies working with our desert climate instead of against it. With a goal of Net Zero Energy use and the mandate that the architecture be reflective of and complementary to the natural beauty of the surrounding desert, the challenge was how to achieve these goals concurrently.

For starters, the overhaul involved installing Big Ass Fans (a main player in the building’s aggressive passive cooling strategy); Solatubes (there are 82 in total strategically spread throughout the facility, providing the building with 100 percent of its daytime lighting needs while also connecting “employees to the daily cycle of the sun, entraining their circadian rhythms, relieving stress and improving productivity”); a big red button that acts as a vampire energy-combating kill switch (located near the front entry, the button cuts off electricity to 95 percent of the building’s non-critical plug loads during non-working hours); and dedicated zen and fitness rooms for employee use.

An 87-foot solar chimney also plays a crucial role in the building’s overall efficiency, second only to the Solatube sun pipes in energy-reducing impact:

Similar to chimneys constructed in ancient adobe or stone buildings, we designed and built a Solar Chimney of our own. It consists of a large, zinc panel-clad structure on top of the existing roof structure. It functions by capturing hot air rising in the office, letting it escape through operable louvers in the Solar Chimney to the outside which encourages a breeze across the workstations in the office as fresh air is drawn in through the building’s operable windows.

Last but not least, DPR took one specific requirement of Net Zero Energy Building Certification, Beauty, to heart:

If one found beauty in a highly-efficient building that generates 100% of its annual energy onsite, they would find our office beautiful. If one found beauty in a building that was contextually appropriate to its natural surroundings, city’s history and name, they would find our office beautiful. And if one found beauty in a building whose future was likely in a landfill but was rescued and restored, they would find our office beautiful. Through the creative ingenuity of our designers and the dedication and risk-taking of our company’s leadership, we have achieved beauty on all fronts.

Lots more on this beautiful indeed transformation at the project's Living Building Challenge case study page. Ariel Schwartz over at Co.Exist also recently published a great profile of the project — a project that can claim bragging rights as being the largest certified net-zero energy building in the world — in which DPR regional manager Dave Elrod describes how the building not only serves as office space for a private company but as a visitor-friendly living laboratory of sorts for others to emulate: "The biggest thing we’ve learned is just how difficult it is for an owner to do any project, let alone a net-zero energy project. Besides being net zero and LEED certified, we also had a goal of being financially responsible. The point was to make it achievable for those who are going to own and live in buildings to think about these kinds of strategies."